Abstract: is a Greek words steganos, meaning

Abstract: A Steganography method of embedding audio or video

information in an image  is presented in this paper. InSteganography is the art and science of hiding communication.
Essentially, the information-hiding process in a steganographic system starts
by identifying redundant bits.we use a
image steganography to send confidential audio or video message secretly. For
hiding the data in an image, we use the least significant bit method of
insertion. All image files are made up of bits,

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!


order now

which
give the colour intensity for each pixel in the image. Any color pixel is made of a combination of
RED-GREEN-BLUE (RGB) wherein each RGB components consists of 8 bits

.
In the 8 bits for each colour, if the least

significant
bit is used to insert the encrypted text, the resultant colour does not

vary
from that of the original colour.

Hence,
our proposed system inserts the twice-encrypted file into an image

file. secret audio or video message is encrypted
with the help of ABE encryption algorithm and then the encrypted audio message
is embedded into a cover image by using LSB technique. And then decrypted the
secret message in the cover image with a specified recipient.

 Keywords:

·       
STEGNOGRAPHY

·       
LSB

·       
ABE

1.Introduction

 

 The word steganography is a Greek
words steganos, meaning “covered, concealed, or protected”, and
graphene meaning “writing”. Steganography is the method of covering
and hiding messages in a medium called a cipher text.

It
is the practice of encoding/embedding secret

information
in a manner such that the existence of the information is invisible. The

original
_les can be referred to as cover text, cover image, or cover audio. After

inserting
the secret message it is referred to as stego-medium. A stego-key is used

for
hiding/encoding process to restrict detection or extraction of the embedded

dataSteganographic
systems, can be divided into two categories, one is in which the very

existence
of the message is kept secret, and non steganographic systems, in which the
existence

of
the message need not be secretThis paper is an attempt uses an image as a cover
medium to hide an audio or video file without

making
noticeable changes to the file structure and contents of the  image based on two Least

Significant
Bit insertion method of the low part of the image.

 general diagram of stegnography               2.Encryption using ABE

Attribute-based
encryption (ABE), introduced by Sahai and Waters (2005), offers an expressive
way to define

asymmetric-key
encryption schemes for policy enforcement based on attributes. Here both a user
secret key and

ciphertext
are associated with sets of attributes. There are two flavours of ABE defined,
i.e. ciphertext-policy

attribute-based encryption (CP-ABE) and key-policy
attribute-based encryption (KP-ABE).

                 Architecture of  ABE Encryption

I will use a CP-ABE Policy In
CP-ABE,

a
user encrypts the data according to

a
predicate (access policy) defined over attributes, such that only the party
that possesses a secret key associated

with
the attribute set satisfying the predicate is able to decrypt the ciphertext,
CP-ABE schemes are more desirable due to their

flexibility allowing encryption according to the
access policy.

 Architecture of both encryption and decryption

3.Algorithm
of CP-ABE:

CP-ABE
Scheme Outline

• Setup. A randomized algorithm Setup(k)
takes in as input a security parameter and provides a setof public parameters
(PK) and the master key values (MK).

 

• Encryption. The algorithm Enc(M, T ,
PK) is a randomized algorithm that takes as input themessage to be encrypted
(M), the access structure T which needs to be satis_ed and the publicparameters
(PK) to output the ciphertext CT. We can say, that the encryption algorithm
embeds the

access
structure in the ciphertext such that only those users with attributes
satisfying T will be ableto decrypt and retrieve the message M.

• Key-Generation. The KeyGen(MK, PK, A)
algorithm takes as input the master key values

(MK),
the public parameters (PK) and the attribute set of the user (A), and outputs
for the user aset of decryption keys SK which con_rms the users possession of
all the attributes in A and no other

external
attribute.

 

• Decryption.
The decryption algorithm Dec(CT, SK, PK) takes as input the ciphertext CT,
theuser secret keys SK and the public parameters PK, and it outputs the
encrypted message (M) if

and
only if the attributes A embedded in SK satisfy the access structure T which
was used whileencrypting the ciphertext CT. i.e If T (A) = 1 then message M is
output else, it outputs?.

 

4.Embedding Process :

In
dealing with LSB coding methodologies (LSB) least significant bit is modified
to embed data. In terms of phase encoding scheme the part of carrier file is to
be replaced with the reference phase which represents hidden data.The LSB is the lowest significant bit in
the byte value of the image pixel. The LSB based image steganography
embeds the secret in the least significant bits of pixel values of the cover
imageThe least signi_cant bit (in other
words, the 8th bit) of some or all of the bytesinside an image is changed to a
bit of the secret message.Increasing or decreasing the value by changing the
LSB does not change the appearance of the image; much so the resultant stego
image looks almost sameas the cover image. In 8 bit images, one bit of
information can be hidden.

 

C(i,j)
is equal to the message bit m of secret massage to be embedded, C(i,j)

remain
unchanged; if not, set the LSB of C(i, j) to m. The message embedding

procedure
is given below-

S(i,j)
= C(i,j) – 1, if LSB(C(i,j)) = 1 and m = 0

S(i.j)
= C(i,j), if LSB(C(i,j)) = m

S(i,j)
= C(i,j) + 1, if LSB(C(i,j)) = 0 and m = 1

where
LSB(C(i, j)) stands for the LSB of cover image C(i,j) and m is the next

message
bit to be embedded.

S(i,j)
is the stego image

As
we already know each pixel is made up of three bytes consisting of either a 1

or
a 0.

For
example, suppose one can hide a message in three pixels of an image (24-bit

colors).
Suppose the original 3 pixels are

 

(11101010
11101000 11001011)

(01100110
11001010 11101000)

(11001001
00100101 11101001)

 

A
steganographic program could hide the letter “J” which has a position
74 into

ASCII
character set and have a binary representation “01001010”, by
altering the

channel
bits of pixels.

 

(11101010
11101001 11001010)

(01100110
11001011 11101000)

 

 (11001001 00100100 11101001)

In
this case, only four bits needed to be changed to insert the character
succesfully.

The
resulting changes that are made to the least signi_cant bits are too small to
be

recognised
by the human eye, so the message is e_ectively hidden. The advantageof LSB
embedding is its simplicity and many techniques use these methods .

LSB
embedding also allows high perceptual transparency.

Data Embedding Algorithm:

The
embedding process is as follows.

Inputs :Cover image, stego-key
and the secret audio file

Output: stego image

Procedure

Step 1: Extract the pixels of the cover
image.

Step
2: Extract the audio file.

 

Step
3: Extract the characters from the Stego key.

 

Step
4: Choose first pixel and pick characters of the Stego key and place it in firstcomponent
of pixel.

 

Step
5: Place some terminating symbol to indicate end of the key. 0 has been used

as
a terminating symbol in this algorithm.

 

Step
6: Insert the audio file  in each first
component of next pixels by

replacing
it.

 

Step
7: Repeat step 6 till all the audio file has been embedded.

 

Step
8: Again place some terminating symbol to indicate end of data.

Step
9: Obtained stego image.

 

 Data
Extraction Algorithm:

The
extraction process is as follows.

Inputs
:Stego-image, stego-key

Output:
Secret audio or video message. Procedure:

Step
1: Extract the pixels of the stego image.

Step
2: Now, start from first pixel and extract stego key characters from first

component
of the pixels. Follow Step3 up to terminating symbol, otherwise follow

step
4.

Step
4: If this extracted key matches with the key entered by the receiver, then

follow
Step 5, otherwise terminate the program.

Step
5: If the key is correct, then go to next pixels and extract secret message

characters
from first component of next pixels. Follow Step 5 till up to terminating

symbol,
otherwise follow step 6.

Step
6: Extract secret message.

 

Audio Encryption Algorithm:

Inputs:
cover image, key and audio file   Output :cipher
text (audio file).

.

1.
The cover and secret images are read and converted into the unit8 type.

2.
The  audio or video file is encrypted.

3.
ABE algorithm can be used to encrypt the secret audio or video file

4.
These encrypted file can be embedded the image using LSB technique.

5.
The stego-image, which is very similar to the original cover image, is send to
the receiver.

6.  while the receiver can receive and the
decrypt the  secret audio file

Example :

                        RGB(cover image)

We use a LSB technique to change the color
pixels in the cover image. the original quality of the image cannot be changed.

It is a original audio file and
then encrypted using attribute based encryption.

The encrypted audio file is,

Conclusion:

A
new approach of embedding an audio or video file into the image using LSB based
image

Steganography
has been successfully developed and implemented as discussed in this paper. The
main aim of this research

work
was embedding of audio or video into image as a case of image steganography. In
test cases, the

audio or video file has been successfully
embedded and extracted from the image